In previous interconnection between equipment, such as between when computer modems are removed from the telephone equipment circuit, the corresponding telephone jack signals remain open. As a result the circuit appears to be ready for communication. However, a more appropriate condition would be a busy-out condition. The approach necessary to produce a busy-out condition is typically a shorted contact between the appropriate pair of wires. Therefore, the busy-out condition has been accomplished by manual shorting of the contacts or designation by the appropriate control equipment that the circuit is not available for communication and the card has been removed. As a result of the added complexity, the decreased reliability, and the added confusion which results in such manual interventions makes it difficult to maintain a reliable communication systems.